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#! /usr/bin/env python
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
from xml.etree import ElementTree
import subprocess
class GstXmlParser(object):
AUDIO_CLASS = 'Codec/Encoder/Audio'
VIDEO_CLASS = 'Codec/Encoder/Video'
def __init__(self):
self._cache = {}
popen = subprocess.Popen(['gst-xmlinspect'], stdout=subprocess.PIPE)
gst_xml_out, __ = popen.communicate()
# the dump is not a proper xml, have more than one root
header = gst_xml_out[:gst_xml_out.find('>') + 1]
body = gst_xml_out[gst_xml_out.find('>') + 1:]
self._gst_xml = header + '<dump>' + body + '</dump>'
def get_mimes(self, element_class):
"""
gst-xmlinspect returns a xml file with the following info
<element>
<name>vorbisenc</name>
<details>
....
<class>Codec/Encoder/Audio</class>
....
</details>
....
<pad-templates>
...
<pad-template>
<name>src</name>
<direction>src</direction>
<presence>always</presence>
<caps>audio/x-vorbis</caps>
</pad-template>
</pad-templates>
Audio: <class>Codec/Encoder/Audio</class>
Video: <class>Codec/Encoder/Audio</class>
"""
if not element_class in self._cache:
mime_types = []
_eroot = ElementTree.fromstring(self._gst_xml)
for gst_element in _eroot.findall('element'):
if gst_element.find('details').find('class').text == \
element_class:
for pad_template in \
gst_element.find('pad-templates').findall('pad-template'):
if pad_template.find('name').text == 'src':
mime_type = pad_template.find('caps').text
if mime_type.find(',') > 0:
mime_type = mime_type[:mime_type.find(',')]
if mime_type != 'unknown/unknown' and\
mime_type not in mime_types:
mime_types.append(mime_type)
self._cache[element_class] = mime_types
return self._cache[element_class]
if __name__ == '__main__':
print "Get info from gst-xmlinspect"
parser = GstXmlParser()
print "Audio types"
print parser.get_mimes(GstXmlParser.AUDIO_CLASS)
print
print "Video types"
print parser.get_mimes(GstXmlParser.VIDEO_CLASS)
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